Suction press roll assembly



July 30, 1940. BERRY 2,209,760

SUCTION PRESS ROLL ASSEMBLY Filed May 28, 1938 2 Shee'ts-Sheet l July30, 1940. E. E. BERRY SUCTION PRESS ROLL ASSEMBLY 42 Shets-Sheet 2 7Filed May 28, 1938 Patented July .30, 1940 UNITED STATES PATENT OFFICE2,209,760 7 SUCTION PRESS ROLL ASSEMBLY Earl E. Berry, Belolt, Wis.,assignor to Beloit Iron Works, Beloit, Wis., a corporation of WisconsinThis invention relates to suction press roll assemblies wherein a wetweb of paper is subjected to localized suction treatments at spacedintervals along the length of travel thereof and wherein water isprevented from re-entering the web between the localized suction areas.

More specifically the invention relates to press roll assemblies havingthe constituent rolls thereof in horizontal alignment and including asuction roll having a top press roll cooperating therewith for"hardening the web before it enters the first nip of the horizontalassembly of rolls.

In the dewatering of wet paper webs by suction, it is customary to passthe webs around a perforated revolving surface having a localizedsuction area. As the web travels beyond the localized suction area,water entrained in the perforations of the revolving surface is thrownback into the web by centrifugal action. This invention now eliminatesthe remoistening of suction treated webs by retaining the waterentrained in the perforations of the revolving surface on which the webis supported until the web is removed from the surface. At the sametime, the invention makes possible a desired long length of travel ofthe web around the surface and a second suction treatment of the webwithout being removed from the surface.

An important feature of this invention is the removal of water from aweb by suction and pressure to harden the web before the same issubjected to an additional suction and pressure operation on the samesupporting surface for the 35 web.

It is, then, an object of this invention to provide suction press rollassemblies for dewatering wet, fibrous webs without remoistening thewebs after the suction treatment.

40 Another object of the invention is to retain water entrained in theperforations of suction roll cylinders after the suction treatment of awet, fibrous web on the cylinder until the web is either removed fromthe cylinder or subjected to a second suction treatment.

Another object of the invention is to provide a horizontal press rollassembly wherein one of the constituent rolls has a separate press rollcooperating therewith to partially dewater a web 50 entering thehorizontal assembly of rolls before it reaches the first nip of theassembly.

A further object of this invention is to provide suction rolls having aplurality of spaced, localized suction areas and means for retainingwater entrained in the perforations of the roll cylinders during theirtravel between the localized suction areas.

A further object of this invention is to prevent the remoistening ofpaper webs traveling around suction rolls after the webs have beensubjected to a suction treatment.

Another object of the invention is to provide a horizontal press rollassembly for dewatering wet paper webs with a suction roll having aplurality of localized suction areas and means for retaining waterentrained in the suction roll cylinder as the web passes on the rollbetween the suction areas.

Other and further objects of the invention will become apparent to thoseskilled in the art from the following detailed description of theannexed sheets of drawings which disclose preferred embodiments of theinvention.

On the drawings:

Figure 1 is a somewhat diagrammatic side elevational view of ahorizontal press roll assembly, with the first roll of the assembly invertical cross section.

Figure 2 is a somewhat diagrammatic side elevational view of anotherform of horizontal press roll assembly according to this inventionshowing the middle roll of the assembly in vertical cross section.

Figure 3 is a somewhat diagrammatic side elevational view of ahorizontal press roll assembly according to this invention with thefirst roll of the assembly shown in vertical cross section.

Figure 4 is a somewhat diagrammatic side e1evational view of anotherform of horizontal press roll assembly according to this inventionshowing the first and third rolls of the assembly in vertical crosssection.

Figure 5 is a transverse vertical cross-sectional view of a suction rolladapted to be used in the assemblies of Figures 1 to 4 inclusive inplace of the suction rolls therein shown and illustrating theconstituent parts of the roll somewhat diagrammatically.

Figure 6 is a longitudinal cross-sectional view, with parts inelevation, taken along the line VI-VI of Figure 4.

As shown on the drawings:

In Figure 1 the reference numeral l0 designates a Fourdrinier formingwire trained around a couch roll II as is customary on Fourdrinier papermaking machines. The couch roll II can have a suction head l2 thereinfor removing water from a web of paper W formed on the wire III as theweb is removed from the wire. The web W is directed under a guide rolll3 first roll l5 of a horizontal press roll assembly according to thisinvention. The horizontal press roll assembly includes rolls l5, l6 andI! having their axes in horizontal alignment and preferably lying in thesame horizontal plane.

The rolls l5 and H are urged against the center roll IE to createpressures at the nips defined by the rolls.

A second felt I 8 is trained over the roll H.

A guide roll l9 laps the felt l8 against the roll I1 before the feltenters the nip between the rolls l6 and I1.

' Guide rolls 20 and 2| are mounted within the loop of the first felt |4so that the felt will meet the web W before the web reaches the firstroll |5.

The roll I5 is a suction roll comprising the usual perforated cylinder22 having a suction conduit 23 therein. The suction conduit 23 has apair of circumferentially spaced heads 24 and 25 defining localizedsuction areas 26 and-21 respectively at the top portion of the roll l5and at the nip defined by the rolls l5 and I6.

Since the suction heads 24 and 25 are spaced circumferentially withinthe cylinder 22, a space 28 is provided between the suction heads. In

accordance with this invention this space 28 is maintained under reducedpressure to prevent water entrained in the perforations of the cylinder22 from being thrown back by centrifugal action into the felt l4 and webW as the same pass between the localized suction areas 26 and 21.

In order to evacuate the space 28, the suction conduit 23 is formed witha slotted housing 29 adapted to receive a slotted rod 30 in rotatablerelation thereto. The rod 3 0 can be rotated to produce any desireddegree of communication between the space 28 and the interior of thesuction conduit 23. The rod 30 thereby acts as a valve for controllingthe pressure in the space 28 A rubber covered top press roll 3| is urgedagainst the suction roll 5 opposite the suction area 26 thereof. Theroll 3| is adjustable peripherally around the top portion of the roll l5as indicated in dotted lines so as to vary the nip between the rolls l5and 3| along the length of the suction area 26,

After the cylinder 22 of the roll l5 passes beyond the suction area 2'!the water retained in the holes of the cylinder is free to drop bygravity and by centrifugal action out of the holes. A moisturecollecting pan 32 is mounted around the under portion of the cylinder 22to receive the discharged water. A moisture collecting pan 33 canlikewise be disposed under the roll IT for collecting water thrown by ordraining from the periphery of the roll. The pans 32 and 33 can beemptied through drains 34 and 35 respectively.

A doctor 36 is provided at the top of the middle roll l6 for cleaningthe periphery of the roll before it enters the first nip of the assemblyand also for preventing water carried by the roll from entering the nip.

In operation of the assembly shown in Figure 1, the web W from theFourdrinier wire l0 meets the felt l4 and is conveyed on the felt aroundthe top of the suction roll |5 where it is subjected to suction at thesuction area 26 and also to a light pressure treatment. This suction andpressure treatment sufilciently dewaters the web so that it can besubjected to high pressures in the first nip of the horizontal assemblyof rolls without being crushed.

onto a felt l4. The felt I4 is trained around the As the web and feltleave the first suction area 26 they travel around the roll l5 to thesecond suction area 21. During the passage between the suction areas 26and 21, however, water sucked into the holes of the roll cylinder 22 isretained in the holes by reduced pressure existing in the space 28between the suction areas. The pressurein this space is regulated so asto prevent the water in the holes of the cylinder from be ing thrownback into the felt and web. As the felt and web contact the secondsuction area 21, they are subjected to an additional suction dewateringtreatment, and, while still under the influence of suction, they arepressed between the rolls l5 and I6 for the additional pressure removalof water.

After the web and felt pass through the nip between the rolls l5 and Hi,the web is separated from the felt and travels around the center rolll6. While on the roll l6, the web enters the nip between the rolls |6and I! and passes through this nip with the felt l8. Additional amountsof water are thus removed from the web. This water can freely draindownwardly out of the nip and away from the web. The felt |8 continuesaround the roll I! while the web W is directed vertically upward fromthe nip over a guide roll 31.

The apparatus shown in Figure 1 therefore provides an initial suctionand light pressure treatment to harden" the web before it enters thenips between the horizontal press rolls. Water is retained in theperforations of the suction roll 22 along the length of travel of theweb and felt between the suction areas so as to prevent the remoisteningof the web and felt.

In the embodiment shown in Figure 2, parts identical with partsdescribed in Figure 1 have been marked with the same reference numeral.

In Figure 2 the horizontal press roll assembly comprises three pressrolls 40, 4| and 42 having their axes in substantially horizontalalignment with the end rolls 40 and 42 pressed against the middle roll4| to define two nips for the assembly.

The middle roll 4| is a suction roll comprising the usual perforatedcylinder 43 and a suction conduit 44 mounted within the cylinder 43. Thesuction conduit has two suction heads 45 and 46 defining suction areas41 and 48 at the nips between the rolls of the assembly. There isthusprovided a space 49 in the cylinder 43 between the suction areas 41and 48. This space 49 can be evacuated by communication with theinterior of the suction conduit 44. For this purpose the conduit 44 isprovided with slotted rod housing portions 50 and 5| adjacent the topsides of the suction heads 45 and 46. Slotted rods 52 and 53 are rotatedin the housings 58 and 5| to act as valves for controlling the pressurein the space 49.

A felt 54 is wrapped around the bottom portion of the roll 40 by meansof a guide roll 55 and is trained over the top of the roll 4|.

Doctors such as 56 and 51 act against the rolls 40 and-42 respectivelyto prevent moisture carried by the rolls from contacting the felt or webtrained around the rolls.

A drip pan 58 is mounted beneath the middle roll 4| for collecting waterdraining from or thrown out of the holes in the roll cylinder 43. Thedrip pan can be emptied by means of a drain 59.

The web W from the Fourdrinier wire I0 is trained over a guide roll 60and against the first roll 40 of the horizontal press assembly. The webon the roll 40 is covered by the felt 54 and the web and felt togetherpass through the first nip of the assembly between the rolls 48 and 4|.The web and felt are subjected to suction as they pass through the nipat the suction area 41. After leaving the suction area 41 the web istrained around the roll 4| on top of the felt 54 over the area 49 of theroll and water is prevented from re-entering the web and felt by reducedpressure in the space 49. As the web and felt enter the second nip ofthe assembly, the same are subjected to suction at the suction area 48.After passage through the second nip, the web is separated from the feltand travels around the third press roll 42.

In the modification shown in Figure 3, parts identical with partsdescribed in Figure 1 are designated by the same reference numerals usedin Figure 1. In the modification shown in Figure 3, however, the suctionconduit 23 within the perforated cylinder 22 has a wide suction head 6|defining a suction area 62 extending from the top of the roll into thefirst nip of the horizontal roll assembly. The web W traveling on thefelt 14 is thus continuallysubjected to suction during its completetravel between the top press roll 3| and the first nip of the horizontalroll assembly. This wide suction area prevents moisture from beingthrown back into the felt or web after the initial light pressing orhardening" operation between the rolls l5 and 3|.

In the embodiment shown in Figure 4, parts corresponding with partsdescribed in Figure 1 have been designated by the same referencenumerals. In Figure 4 the felt I4 is trained directly around the roll I5so that the web W first contacts the felt on the roll, for travelthereon over the suction areas 26 and 21 and through the first nip ofthe horizontal press roll assembly. The web is then removed from thefelt and travels around the under side of the middle roll I6 intocontact with the felt l8 for passage upwardly through the second nip ofthe assembly defined by the roll l6 and a second suction roll 18receiving the felt I8 therearound. The roll I0 comprises the usualperforated cylinder ll having a suction conduit 12 therein. The suctionconduit has a suction head 13 defining a suction area 14 at the nipbetween the rolls I6 and I0 and extending below the nip to initially drythe felt 18 before the felt contacts the web on the roll.

The suction conduit 12 has a second suction head 15 defining a suctionarea 16 at the top portion of the roll Ill. The space 11 between thesuction areas 14 and 16 is maintained under reduced pressure to preventwater entrained in the holes of the cylinder H frombeing thrown backinto the felt l8 and web W. For the purpose of partially evacuating thespace 11 the suction conduit is provided with a cylindrical housingportion 18 receiving a slotted rod 19 in rotatable relation therein. Therod 18 can act as a valve to establish a desired amount of communicationbetween the space H and the interior of the suction conduit.

The web W is carried on the felt [8 over the suction area 16 and is thenseparated from the felt for passage to additional press rolls ordirectly into the drier section of the paper machine. The felt l8continues around the roll 10.

If desired a drip pan can be mounted beneath the middle roll IS. Thedrip pan can be emptied by means of a drain 8|.

In the operation of the assembly shown in Figure 4, the web W is firstsubjected to a suction and a light pressure treatment at the suctionarea 28 of the first roll l5. This treatment hardens the web so that thesame can be subjected to the higher pressures in the downward passagenip of the horizontal press roll assembly. The web is then subjected toa second suction pressure treatment in the upward passage nip of theassembly and finally to a forced suction treatment over the suction area18.

As best shown in Figure 6,"the rolls such as 15 have end seals 82 forthe suction areas such as 21 and end seals 83 for the space 28 betweenthe suction heads 24 and 25. These end seals 82 and 83 can he slid alongthe suction conduit 23 to vary the width of the evacuated areas. Asshown. the suction area 21 communicates with the interior. of theconduit 23 through an opening 84 in the central portion of the conduit.However, the space 28 only communicates with the interior of the suctionconduit 23 through the opening provided by the slotted rod 38. The slotin the rod may be coextensive with the opening 84 while the remainingportion of the rod is solid. The rod extends through an end seal 83 andmay have a head portion 30a thereon for manual turning of the rod toadjust the size of the slot opening.

As is customary, the end seals 82 and 83 are adiusted longitudinallywithin the cylinder 22 to define suction areas coextensive in width withthe paper web being passed around the roll.

In the embodiment of the roll l5 shown in Figure 5, parts correspondingto parts described in Figure l have been designated with the'samereference numerals. In Figure 5, however, the space 28 between thesuction heads 24 and 25 is maintained under reduced pressure from aseparate source of vacuum than the interior of the conduit 23. Thus thespace 28 can be evacuated through a pipe connected with a separatesuction pump. The pipe 85 may extend through a trunnion of the suctionroll and be connected to a separate suction pump.

From the above descriptions it should be understood that this inventionprovides for the extraction of water from wet, fibrous webs by suctionand pressure and prevents water from being thrown back into the fibrouswebs between suction treatments.

The horizontal press roll assemblies of this invention provide upwardand downward passage nips for pressing water from. wet, fibrous webs.The upward passage nips of the assembly permit gravity drainage of watertherefrom.

In order to prevent crushing of a newly formed wet, fibrous web, in anip of the horizontal press roll assembly the web can be given a lightpressure and suction-treatment to harden the same before it enters thefirst nip of the horizontal roll assembly.

I am aware that many changes may be made and numerous details ofconstruction may be varied through a wide range without departing fromthe principles of this invention, and I, therefore. do not purposelimiting the patent granted hereon otherwise than necessitated by theprior art.

I claim as my invention:

1. A press roll assembly for dewatering newly formed wet, soggy webswhich comprises a perforate cylinder adapted to receive the webtherearound, a pair of press rolls in peripheral pressure relation withthe cylinder at peripherally spaced points thereon, a suction conduitdefining spaced localized suction areas at the nips between the rollsand cylinders, and separate suction means acting from within thecylinder on that portion thereof carryingthe web between the localizedsuction areas for eliminating discharge of water carried by theperforations of the cylinder into the web.

2. A press roll assembly for dewatering wet, soggy webs which comprisesa perforate cylinder adapted to receive the wet web therearound, a pairof rolls in peripheral pressure relation with the cylinder atperipherally spaced points therealong, a suction conduit in the cylinderhaving a pair of head portions defining spaced localized suction areasat the nips between the rolls and cylinder, said suction conduitdefining a space in the cylinder between the suction areas, and valvemeans joining said space with the interior of the suction conduitwhereby the space is maintained under reduced pressure for eliminatingthe discharge of water from the cylinder into the web carried thereon.

3. A press roll assembly comprising a suction roll having a pair ofperipherally spaced localized suction areas, separate rolls cooperatingwith said suction roll at each of said suction areas to define therewitha pair of pressure nips in spaced relation from each other, meansdirecting a wet web of paper around the suction roll over the suctionareas and through the nips, and means acting from within the suctionroll to subject to suction that portion of the suction roll conveyingthe web between the localized suction areas.

4. A horizontal press roll assembly comprising a plurality of rolls inperipheral pressure relation having their axes lying in the samehorizontal plane to define at least one vertical passage niptherebetween, a felt lapped around part of the periphery of the firstroll for guiding a wet, fibrous web through the first nip of thehorizontal assembly, a press roll acting against the first ,roll andfelt thereon at a point ahead of said first nip of the horizontalassembly to define with the first roll an initial pressure nip, andsuction means acting from within said first roll to suck liquid from theinitial pressure nip and from the first nip of the horizontal rollassembly.

5. A horizontal press roll assembly comprising a middle roll, a roll oneach side of the middle roll in peripheral pressure relation therewith,said rolls having their axes lying in substantially the same horizontalplane and adapted to receive a web of paper through the vertical passagenips defined thereby, a separate press roll acting against the firstroll of the horizontal assembly to'define therewith an initial pressurenip ahead of the first nip of said assembly, and means acting fromwithin said first roll to suck water from the initial nip and from saidfirst nip of the horizontal assembly.

6. A dewatering roll assembly adapted to receive a wet, soggy web ofpaper directly from its forming surface comprising three rolls inperipheral pressure relation having their axes lying in substantiallythe same horizontal plane, said rolls defining therebetween verticalupward and downward passage pressure nips for the web of paper, a toppress roll cooperating with the first roll of the horizontally alignedrolls to define therewith an additional pressure nip ahead of the firstnip of the horizontally aligned rolls, a felt for conveying the webaround the first roll through the nip between the top press roll andfirst roll and into the downward passage nip, a second felt trainedaround the third roll for conveying the web through the upward passagenip, and common means acting from Within the first roll to suck liquidfrom the two nips partially defined by said first roll.

7. A dewatering roll assembly adapted to receive a newly formed wet,soggy web of paper directly from its forming surface comprising threehorizontally aligned rolls in peripheral pressure relation, the middleroll of said three rolls having spaced localized suction areas at thenips defined by the rolls, and suction means acting from within saidmiddle roll to subject to suction that portion of the middle rollconveying the web between the nips of the assembly.

8. A press roll assembly for dewatering wet, soggy webs comprising threehorizontally aligned rolls in peripheral pressure relation, means insaid first and third rolls defining localized suction areas at the nipsbetween the rolls, said means within the first and third rolls alsodefining additional localized suction areas at points on said rollsspaced from said nips, and a press roll cooperating with said first rollat the additional suction area thereof for initially subjecting the webto a suction and pressure operation before it enters the first nip ofthe horizontally aligned rolls.

9. A press roll assembly comprising three rolls in peripheral pressurerelation having their axes lying. in substantially the same horizontalplane, suction conduits in said first and third rolls defining localizedsuction areas at the nips between the rolls and additional localizedsuction areas at the tops of the rolls, said suction conduits definingspaces in the rolls between the localized suction areas, and means forevacuating said spaces to prevent remoistening of the web as it travelsover the rolls between the localized suction areas thereof.

10. In a press roll assembly, a suction roll comprising a hollowperforated cylinder, a suction conduit in said cylinder having a pair ofperipherally spaced suction heads defining localized suction areas onthe cylinder, a passageway through said suction conduit between thesuction heads, and a valve controlling the efiective size of thepassageway for regulating the pressure on that portion of the cylinderbetween the localized suction areas.

11. A suction roll comprising a hollow perforate cylinder, a suctionconduit in said cylinder having a pair of spaced suction heads defininglocalized suction areas at peripherally spaced sections of the cylinder,a cylindrical housing in said suction conduit between the suction headsthereof having an opening therethrough, a rod rotatably mounted in saidhousing having a slotted portion for venting that space in the cylinderbetween the suction heads to the interior of the suction conduit, andmeans for rotating the rod to regulate the effective communicationbetween said space and the interior of the conduit.

12. A suction press roll assembly comprising a suction roll having arotatable liquids-pervious cylinder, a stationary suction conduit insaid cylinder having a pair of spaced suction heads defining localizedhigh vacuum areas at peripherally spaced sections of the cylinder indirect communication with the conduit, separate press rolls cooperatingwith said cylinder adjacent each localized high vacuum area to definewith the cylinder a pair of spaced pressure nips, said cylinder inoperation receiving a paper web therearound over the high vacuum areasand through the nips, said conduit and suction heads defining alocalized low vacuum space in said cylinder between said localized highvacuum areas, end seals for said space, means providing a passagewaybetween said low vacuum space and the interior of said conduit forevacuating said space, and a valve cooperating with said means toregulate the pressure in said space and on that portion oi the cylinderbetween the" localized high vacuum areas for preventing remoistening oithe paper web as it travels over the cylinder between the high vacuumareas without wasting suction.

EARL E. BERRY.

